Topic
Pipe flow
About: Pipe flow is a research topic. Over the lifetime, 13826 publications have been published within this topic receiving 351605 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this article, quadrant analysis is applied to spatial disturbances of time-averaged velocity components, using the experimental data from flow over two-dimensional regular transverse square-bar roughness.
Abstract: We explore a new application of the quadrant method in the context of the double-averaged Navier–Stokes equations for studying open channel flow near rough beds. Quadrant analysis is applied to spatial disturbances of time-averaged velocity components, using the experimental data from flow over two-dimensional regular transverse square-bar roughness. The spatial velocity disturbances change periodically performing a full cycle over a single roughness element, so that the quadrant diagrams are regular closed orbits. A colour code is used to produce a quadrant map of the flow cross-section, which reveals contributions from each quadrant to the time-averaged momentum transfer.
87 citations
TL;DR: In this paper, the heat transfer and friction characteristics of a decaying swirl flow were investigated experimentally and the results were correlated in the form of Nusselt number as a function of Reynolds number, Prandtl number and the vane angle as Nu=0.133Re0.65Pr0.4(1+tan θ)0.406
87 citations
TL;DR: Fully developed flow in an infinite helically coiled pipe is studied, motivated by physiological applications in this article, where the effects of curvature and torsion on the flow are investigated.
Abstract: Fully developed flow in an infinite helically coiled pipe is studied, motivated by physiological applications. Most of the bends in the mammalian arterial system curve in a genuinely three-dimensional way, so that the arterial centreline has not only curvature but torsion and can be modelled by a helix. Flow in a helically symmetric pipe generalizes related problems in axisymmetry (Dean flow) and two-dimensionality, but the geometry ensures that even irrotational flow has a cross-pipe component. Fully developed helical flows driven by a steady pressure gradient are studied analytically and numerically. Varying the radius and pitch of the helical pipe, the effects of curvature and torsion on the flow are investigated.
86 citations
TL;DR: In this article, multi-point velocity measurements have been performed in turbulent pipe flow at ReD = 1.5 × 105 and combined with cross-spectral and proper orthogonal decomposition analysis to elucidate information on the structure of the large- and very-large-scale motions in the outer layer of wall-bounded flows.
Abstract: Multi-point velocity measurements have been performed in turbulent pipe flow at ReD = 1.5 × 105 and combined with cross-spectral and proper orthogonal decomposition analysis to elucidate information on the structure of the large- and very-large-scale motions in the outer layer of wall-bounded flows. The results indicate that in the outer layer the large-scale motions (LSM) may be composed of detached eddies with a wide range of azimuthal scales, whereas in the logarithmic layer they are attached. The very-large-scale motions (VLSM) have large radial scales, are concentrated around a single azimuthal mode and make a smaller angle with the wall compared to the LSM. The results support a hypothesis that only the detached LSM in the outer layer align to form the VLSM.
86 citations
TL;DR: In this article, Frigaard et al. showed that there is a true rigid plug for a sufficiently small amplitude long wavelength perturbation of the uniform plane channel and provided a comparison between analytical estimates for the breaking amplitude and numerical computations using the augmented Lagrangian method.
Abstract: In this paper we complete the analysis of the flow of a Bingham fluid along a wavy-walled channel. We confirm numerically the results of [I. Frigaard, D. Ryan, Flow of a visco-plastic fluid in a channel of slowly varying width, J. Non-Newt. Fluid Mech. 123 (2004) 67–83], that there is a true rigid plug for a sufficiently small amplitude long wavelength perturbation of the uniform plane channel. For larger amplitude width perturbations the plug breaks and we provide a comparison between analytical estimates for the breaking amplitude and numerical computations using the augmented Lagrangian method. Plug breaking arises due to the creation of significant extensional stresses within the unyielded part of the fluid. When the plug breaks the extensional stresses govern the structure of the flow within the pseudo-plug. We provide a complete asymptotic solution for the flow in this situation, and compare against numerical computations. In the second part of the paper, we study the efficacity of viscosity regularisation methods for computing this type of flow. We show that accurate resolution of yield surface positions requires proper control of the numerical residuals and having a favourable ratio of regularisation error to critical strain rate. We show that failure to manage these errors means that regularisation methods can produce completely erroneous predictions of the yield surfaces, e.g. predicting broken plug regions when they are in fact intact. For general lubrication-type flows one does not have an estimate of these errors.
86 citations